A survey of 105 members of the Royal College of Ophthalmologists to be published today found that only 48 per cent were able to get access to Lucentis and Macugen.

However, most primary care trusts (PCTs) will only pay for the drug in certain situations, such as if the patient is already blind in their other eye. Only 10 per cent of specialists said they could obtain the drug Avastin, a parent drug of Lucentis developed to treat colorectal cancer. Even though it is unlicenced, some specialists have been using it to treat wet AMD because it is significantly cheaper.

Miss Brenda Billington, president of the Royal College, has written to Patricia Hewitt, the Health Secretary, to highlight the lack of availability of the drugs.

She said: "The national picture is one of frustration."

Wet AMD occurs when fragile, abnormal blood vessels grow behind the retina, leading to the leaking of fluid and blood, and eventually scar tissue forming on the macula - the central part of the retina at the back of the eye responsible for "straight-ahead'' vision.

Lucentis, Macugen and Avastin are known as anti-vegf treatments because they counteract the action of VEGF proteins involved in the growth of new blood vessels. Every year there are around 26,000 new cases, making it the biggest cause of blindness. Around 7,000 can benefit from the existing treatment photodynamic therapy (PDT). However, others cannot and unless their doctor can obtain anti-vegf drugs they are left without treatment.

Steve Winyard, of the Royal National Institute of the Blind, said: "PCTs need to start funding treatments now so that patients can get hold of them urgently. There is no excuse for further delays."

A spokesman of the Department of Health said: "Macugen and Lucentis are now licensed and doctors should prescribe these to patients with AMD if they believe it is the right treatment for the patients and the PCT agrees.

"Nice [the National Institute for Health and Clinical Excellence] is appraising both drugs but we have made very clear that funding for either treatment should not be withheld simply because of a lack of guidance from Nice."

Nice decides which treatments the NHS should fund.

Lucentis is seen as the gold standard treatment but it costs the NHS £1,700 per injection - almost £24,000 per patient for a full course of treatment.

One consultant ophthalmologist in London, who did not want to be named, yesterday described how his local PCT resorted to "stone-walling and foot dragging" to refuse or delay providing the drug.

Trials suggest Macugen improves eyesight in 10-15 per cent of patients. It costs £1,300 per injection and treatment is required every six weeks rather than once a month as with Lucentis.

Avastin costs £600 if the recommended protocol is followed, but some doctors have reduced the cost to a fraction by splitting up the large doses of the drug, developed for combat colectoral cancer.